Large parts of eastern Australia were placed on alert on Sunday afternoon for severe thunderstorms, with further storms and flood risks expected on Monday, the Australian Bureau of Meteorology said.
The bureau issued a severe thunderstorm warning on Sunday afternoon for Sydney, the wider Wollongong area, and parts of the Blue Mountains, Hawkesbury, Gosford, Wyong, and the Wollondilly and Wingecarribee regions. According to the bureau, a broad band of storms had already affected western New South Wales.
Severe thunderstorms, which can bring hail, storm-force winds, flash flooding and power outages, were likely on Sunday afternoon across a vast area, including southern Queensland, western New South Wales, the ACT and eastern Victoria. In the central-western part of New South Wales, wind gusts of up to 100 kilometres per hour were recorded around midday on Sunday.
Bureau meteorologist David Crock stated that the storm system affected multiple states and was unusually large. He explained that a high-pressure area had been sitting over the Tasman Sea for the past 10 days, blocking weather fronts and bringing storms and rain to southern Queensland. "Eventually, you get a system strong enough to push that blocking pattern aside, and that usually brings severe weather with it," Crock said. He added that a cold front was moving in from the west on Sunday afternoon, drawing tropical moisture from the north and bringing stormy conditions to central New South Wales and Canberra.
"We have a large band of storms stretching from the Snowy Mountains to the Queensland border. Behind it, we are watching to see if another band will develop," Crock said. Storm activity is likely to continue through Sunday evening and into Monday in northern New South Wales and southern Queensland as the cold front continues to move. "Monday is the last big hit from this system, and that will be a great relief for people in south-east Queensland," Crock said.
Southern parts of Queensland have experienced a weather "shock" over the past week, Crock said. Eight flood warnings were in effect in southern Queensland following days of heavy rain. The Mary River downstream of Gympie is expected to reach major flood levels at Tiaro on Sunday evening and during Monday. After a very dry September, southern parts of the state recorded rainfall in October that was "many times above average" for that month, Crock said. Areas around the Sunshine Coast received between 200 and 400 millimetres of rain over the past week.
Coastal squalls are expected in Victoria and Tasmania in the south-east of the country, while snow is falling above 800 metres in Tasmania. In Western Australia, cooler weather continues on Monday, with possible showers in parts of the south-west. The bureau's current long-range forecast for the period from November to January indicates that rainfall is likely to be above average across most of the country, except in the far north and a large part of Tasmania. The bureau's long-term climate data shows that Australia has warmed by approximately 1.5 degrees Celsius since 1910 due to global warming.
